JPS63189623A - Auxiliary air flow controller - Google Patents

Abstract

PURPOSE:To enable the highly precise control of preliminary air rate by separating a preliminary air passage into two parallel passages, one having a solenoid valve therein and the other having a thermosensitive valve therein. CONSTITUTION:A preliminary air passage 21 is separated into parallel passage parts. The primary passage part 24 contains a solenoid valve 26 which opens and closes in accordance with the operating condition of an engine and the secondary passage part 25 contains a thermosensitive valve 27 which opens and closes in accordance with the temperature of cooling water of the engine. The preliminary air rate at the idling time may then be controlled by the solenoid valve 26 and the thermosensitive valve 27 which are arranged in parallel with each other so that the air flow rate is controlled in the narrower range by both the valves and at the warming-up time the thermosensitive valve 27 closes the secondary passage part 25. And the preliminary air flow rate in the primary passage part 24 only is controlled by the solenoid valve 26 so that the air flow rate may be placed under the stable and precise control without adverse effect from the variation in temperature of engine cooling water.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of the Invention The present invention relates to an auxiliary air amount control device installed in an intake system of an internal combustion engine to stabilize the idling speed.

BACKGROUND OF THE INVENTION As an auxiliary air amount control device during idling operation in a gasoline engine for an automobile, the one shown in FIG. 3 is known (for example, see Japanese Patent Laid-Open No. 57-9380).

To explain the outline, an auxiliary air passage l, which is provided in the middle of an intake passage (not shown) and communicates the upstream side and the downstream side of the throttle valve, is connected to the valve housing 3 of the electromagnetic valve 2 and the side part of the valve housing 3. A fixed solenoid casing 4 is interposed, and an engine cooling water passage 5 is provided on the outside of the solenoid casing 4.
Inside there is a solenoid coil 6 and a solenoid coil 6.
The plunger 8 is slidably housed in the plunger 8 and has a driving rod 7 at its tip. On the other hand, inside the valve housing 3, the outlet portion 1a of the auxiliary air passage 1 is open, and an air introduction chamber 11 is formed, which is partitioned by an annular seat portion 9.10 at both ends and a guide portion 12 at one end. A piston rod 14 is connected to the driving rod 7 and has its other end slidably held by the adjusting end wall 13, and each of the seat portions 9. It has valve bodies 15 and 16 that open and close the air introduction chamber 11 by simultaneously opening and closing orifices 9a and 10a formed in lO, and the valve bodies 15 and 16 are connected to the adjusting end wall! 3
It is biased in the closing direction by a spring 17 attached to the side. Further, the spring force of the spring 17 is applied to the valve bodies 15 and 16 at the seat portion 9. lO orifice 9a, 1
It is set so as to balance the spring force of the coil spring 18 on the proximal end side of the plunger 8 at the position where 0a is closed. On the other hand, engine cooling water is circulated around the outer periphery of the solenoid casing 4 via the engine cooling water passage 5 as described above.

Then, the solenoid coil 6 is energized/de-energized (
For example, the plunger 8. By moving the drive rod 7 and piston rod 14 in the axial direction, the valve bodies 15 and 16 are opened and closed, thereby controlling the total flow rate of auxiliary air into the air introduction chamber 11. Here, in the initial stage of engine startup, the engine cooling water remains at a low temperature and does not have a thermal effect on the solenoid coil 6.
As shown in the figure, the valve body 1 is
5.1B opens the orifice 9a and lOa wide and adjusts the auxiliary air flow rate to approximately 50a/sin to 80a/sin depending on the duty.
Increase to 0 Q/tpin. This increases the idling speed and warms up the engine. After warming up,
The temperature of the above-mentioned cooling water rises, and this high-temperature cooling water heats the solenoid coil 6 to increase the internal resistance of the solenoid coil 6, thereby reducing the magnetic force and reducing the opening amount of the valve bodies 15 and 16. control, for example 100%
The amount of auxiliary air when the duty is input is approximately 301/
This is to prevent the vehicle from running out of control.

Problems to be Solved by the Invention However, in the above-mentioned conventional auxiliary air flow rate control device, one electromagnetic valve 2 controls the entire flow range of the required air flow rate, that is, from about 5012/min to 800Q at low temperature startup. /fllin, 8QOQ/mi after warming up
It is necessary to control the entire flow rate range from n to 3300 ff/min, and therefore the time during which the electromagnetic valve 2 is being controlled becomes large. Moreover, after the warm-up, the valve body 15,1
Since the control of No. 6 is dependent on the engine cooling water temperature, the control becomes unstable. In other words, the cooling water temperature is generally unstable, and becomes even more unstable when auxiliary equipment is activated, but since it is controlled by this water temperature, the auxiliary It becomes difficult to control the amount of air stably and with high precision, resulting in a problem that idling rotation becomes unstable.

Means for Solving the Problems The present invention was devised in view of the problems of the above-mentioned auxiliary air flow rate control device. A solenoid valve that opens and closes according to the operating state of the engine is arranged in the first passage on one side, and a temperature-sensitive valve that opens and closes according to the engine cooling water temperature is arranged in the second passage on the other side. It is said that

Effects According to the invention configured as described above, the amount of auxiliary air during idling is controlled by both the electromagnetic valve and the temperature-sensitive valve, which are arranged in parallel. In addition, after warming up, the temperature-sensitive valve closes the second passage, and the electromagnetic valve controls the flow rate of the auxiliary air that flows only through the first passage.
Stable and highly accurate control can be performed without being affected by fluctuations in engine cooling water temperature.

Example Hereinafter, embodiments of the present invention will be described in detail based on the drawings.

FIG. 1 shows an embodiment of the auxiliary air amount control device according to the present invention, and reference numeral 21 in the figure indicates an auxiliary air passage (not shown) provided in the middle of the intake passage that communicates the upstream side and the downstream side of the throttle valve. , 22 is a valve housing interposed in the middle of the auxiliary air passage 21, 23 is a solenoid casing fixed to the side of the valve housing 22, and the auxiliary air passage 21 is located inside the valve housing 22. 1st in
A passage portion 24 and a second passage portion 25 are branched in parallel, and a solenoid valve 26 is provided in the first passage portion 24.
However, the temperature-sensitive valves 27 are arranged in parallel in the second passage section 25, respectively.

The electromagnetic valve 26 is configured as shown in FIG.
Inside the solenoid casing 23, there are provided a solenoid coil 28, a plunger 30 having a drive rod 29 at its tip, and a coil spring 31a that urges the plunger 30 to the left in the figure, as in the prior art. Further, inside the valve housing 22, a first passage portion 24 is provided.
An annular seat part 32 provided at the entrance end of the annular seat part 32 and one end connected to the drive rod 29 via a guide part 33,
A piston rod 35 whose other end is slidably supported within the adjusting end wall 34, and an orifice 32a formed in the seat portion 32, which is fixed approximately at the center of the piston rod 35, opens and closes the first passage. A substantially conical valve body 36 that opens and closes the portion 24 is provided. This valve body 36 has a coil spring 31b mounted between it and the adjusting end wall 34.
is biased toward the right (closed direction) in the figure. Further, the electromagnetic valve 26 is driven and controlled by the output signal of a control circuit (not shown) that inputs signals from the engine operating state, such as a rotation speed sensor and an engine temperature sensor, and thereby controls the opening and closing of the valve body 36. ing. The spring forces of both the coil springs 31a and 31b are set so as to be balanced when the valve body 36 is in the closed position.

On the other hand, the temperature-sensitive valve 27 provided at the lower end of the valve housing 22 is fixed to the outer end of an operating hole 37 formed laterally across the second passage section 25 of the valve body. 38 and the valve body 3 via the rod 39.
8 and a cylindrical valve body 40 that opens and closes the second passage portion 25 while sliding within the operating hole 37.

The inside of the valve body 38 is divided into two chambers by a diaphragm 41, and the outer chamber is filled with wax pellets 42 and the inner chamber is filled with a fluid 43. A passage 44 for guiding engine cooling water is provided outside the engine. The valve body 40 also has a coil spring 4 attached to the tip side.
5 in the left direction (opening direction) in the figure.

The operation of this embodiment based on the above configuration will be explained below. In other words, when the engine is idling after starting at a low temperature,
The temperature of the cooling water introduced into the passage 44 is low, and while the wax pellets 42 expand, the valve body 40 of the temperature-sensitive valve 27
The coil spring 45 urges leftward and holds the fully open position (dotted chain line position), while the electromagnetic valve 26
is driven to open the valve body 36. Therefore, the auxiliary air that has flowed into the valve housing 22 is supplied to the engine through both the first passage section 24 and the second passage section 25 as shown by the arrows in the figure, and the flow rate thereof is as shown in FIG. As shown in the example, the initial flow rate is approximately 550 Q/min, which is higher than that of the conventional model.
The characteristic is that the current increases from 800 (1/min) at a constant small upward slope in proportion to the current applied to the solenoid coil 28. Therefore, the idling speed increases quickly and stably. After the aircraft, the wax pellets 42 of the temperature-sensitive valve 27 are warmed by the high-temperature cooling water and expand to press the diaphragm 41 to the right. , gradually moves in the closing direction against the spring force of the coil spring 45 to close the second passage portions 2 and 5. On the other hand, the electromagnetic valve 26 controls the auxiliary air flow rate to the opening of the orifice 32a by a control circuit (not shown). For example, the second
Approximately 100 Q/min to 300 Q as shown
/min. Therefore, after warming up, the electromagnetic valve 26 controls the small amount of auxiliary air that passes only through the first passage section 24.
The control period becomes smaller and highly accurate control becomes possible.

In the above embodiment, the temperature-sensitive bulb 27 is made of wax pellets 42, but it is also possible to use other materials such as a shape memory alloy material.

Further, in the above embodiment, the opening and closing of the first passage portion 24 is controlled by one orifice 32a and one valve body 36 that fits therein, but the invention is not limited thereto. It may also be configured such that two orifices are disposed facing each other in the passage section 24, and a valve body is adapted to each of these orifices so that the axial force acting on each valve body is balanced by the suction negative pressure on the outlet side of the passage. .

Effects of the Invention As is clear from the above explanation, according to the auxiliary air amount control device according to the present invention, parallel branched passage portions are formed in the middle of the auxiliary air passage, and the first passage on one side An electromagnetic valve that opens and closes depending on the operating state of the engine is placed in one section, and a temperature-sensitive valve that opens and closes depending on the engine cooling water temperature is placed in the second passage section on the other side. Since the total amount of air is controlled by two valves, the time required for each valve to be controlled can be reduced.
This allows highly accurate control of the amount of auxiliary air.

Moreover, after warming up, the passage on the other side is simply closed off using the temperature-sensitive valve, and only the amount of air passing through the sword passage can be controlled using the electromagnetic valve, which affects fluctuations in the cooling water temperature. This enables stable and highly accurate control without
Idle rotation can be stabilized.

Furthermore, the structure of the entire device is simplified, and therefore more accurate and reliable control can be obtained.

[Brief explanation of the drawing]

FIG. 1 is a sectional view showing an embodiment of the present invention, FIG. 2 is a characteristic diagram of the auxiliary air flow rate control of this embodiment, FIG. 3 is a sectional view showing a conventional auxiliary air amount control device, and FIG. FIG. 3 is a characteristic diagram of auxiliary air flow rate control by the conventional device. 21... Auxiliary air passage, 24... First passage part, 25
...Second passage section, 26...Solenoid valve, 27...
Temperature sensitive valve. Other 2 people Figure 1 Figure 2 27 -------Thinking N ruble lυV Duty (''/, )- Figure 3 Figure 4

Claims (1)

[Claims] (1) A parallel branched passage is formed in the middle of the auxiliary air passage, and an electromagnetic valve that opens and closes depending on the operating state of the engine is arranged in the first passage on one side, and a second passage on the other side.
An auxiliary air amount control device characterized in that a temperature-sensitive valve that opens and closes depending on the engine cooling water temperature is arranged in a passage.